By Kathleen Mulpeter

One of the leading causes of death among young children is complications from extreme premature birth (or birth before 28 weeks). But scientists have developed a new system that could potentially help premature babies born as early as 23 or 24 weeks: an artificial womb designed to mimic the conditions inside a mother's uterus.

The device is a clear plastic bag containing synthetic amniotic fluid. An "umbilical cord" attached to a machine outside the bag removes carbon dioxide and delivers oxygen and nutrients to the fetus. Researchers from the Children's Hospital of Philadelphia have tested the technology on eight preterm lambs who were at a developmental stage similar to a 23- or 24-week-gestation human infant.

Photo: Children's Hospital of Philadelphia

RELATED: 15 Factors That Affect a Woman's Fertility

Their results, published yesterday in the journal Nature Communicationswere encouraging: The lambs were kept in the artificial womb for up to 28 days, and showed normal growth, organ maturation, and lung and brain development. They even grew coats of wool, and opened their eyes. 

In the future, this device could potentially help extremely premature babies continue to develop after they're born. “These infants have an urgent need for a bridge between the mother’s womb and the outside world,” lead researcher and fetal surgeon Alan W. Flake, MD, said in a press release. About 30,000 babies are born younger than 26 weeks each year. 

NPR reports that experts are raising ethical concerns about an artificial womb, including whether it would ever be fair to test the technology on humans. But if clinical trials are successful, Dr. Flake envisions that 10 years from now, artificial wombs might replace incubators and ventilators for extremely premature infants. "This system is potentially far superior to what hospitals can currently do for a 23-week-old baby born at the cusp of viability," he said.